diff --git a/radicle-surf/src/error.rs b/radicle-surf/src/error.rs
index cac2a46..7bd5954 100644
--- a/radicle-surf/src/error.rs
+++ b/radicle-surf/src/error.rs
@@ -21,6 +21,7 @@
 use crate::{commit, diff, fs, glob, namespace, refs, repo};
 use thiserror::Error;
 
+/// The crate level error type that wraps up module level error types.
 #[derive(Debug, Error)]
 #[non_exhaustive]
 pub enum Error {
diff --git a/radicle-surf/src/lib.rs b/radicle-surf/src/lib.rs
index 989319c..8b3b5bd 100644
--- a/radicle-surf/src/lib.rs
+++ b/radicle-surf/src/lib.rs
@@ -36,7 +36,7 @@
 pub use git_ref_format;
 
 /// Represents an object id in Git. Re-exported from `radicle-git-ext`.
-pub use radicle_git_ext::Oid;
+pub type Oid = radicle_git_ext::Oid;
 
 pub mod blob;
 pub mod diff;
diff --git a/radicle-surf/src/repo.rs b/radicle-surf/src/repo.rs
index 9ef689a..c6557a8 100644
--- a/radicle-surf/src/repo.rs
+++ b/radicle-surf/src/repo.rs
@@ -375,19 +375,22 @@ impl Repository {
     ///
     /// # Arguments
     ///
-    /// `commit_oid` - The object ID of the commit
     /// `field` - the name of the header field containing the signature block;
     ///           pass `None` to extract the default 'gpgsig'
     pub fn extract_signature(
         &self,
-        commit_oid: &Oid,
+        commit: impl ToCommit,
         field: Option<&str>,
     ) -> Result<Option<Signature>, Error> {
         // Match is necessary here because according to the documentation for
         // git_commit_extract_signature at
         // https://libgit2.org/libgit2/#HEAD/group/commit/git_commit_extract_signature
         // the return value for a commit without a signature will be GIT_ENOTFOUND
-        match self.inner.extract_signature(commit_oid, field) {
+        let commit = commit
+            .to_commit(self)
+            .map_err(|e| Error::ToCommit(e.into()))?;
+
+        match self.inner.extract_signature(&commit.id, field) {
             Err(error) => {
                 if error.code() == git2::ErrorCode::NotFound {
                     Ok(None)
diff --git a/radicle-surf/t/src/code_browsing.rs b/radicle-surf/t/src/code_browsing.rs
index 60e1f23..2402f36 100644
--- a/radicle-surf/t/src/code_browsing.rs
+++ b/radicle-surf/t/src/code_browsing.rs
@@ -80,3 +80,21 @@ fn test_commit_history() {
 
     assert_eq!(h1.head().id, h2.head().id);
 }
+
+#[test]
+fn test_commit_signature() {
+    let repo = Repository::open(GIT_PLATINUM).unwrap();
+    let commit_with_signature = "e24124b7538658220b5aaf3b6ef53758f0a106dc";
+    let signature = repo.extract_signature(commit_with_signature, None).unwrap();
+    assert!(signature.is_some());
+
+    let commit_without_signature = "80bacafba303bf0cdf6142921f430ff265f25095";
+    let signature = repo
+        .extract_signature(commit_without_signature, None)
+        .unwrap();
+    assert!(signature.is_none());
+
+    let commit_nonexist = "8080808080";
+    let signature = repo.extract_signature(commit_nonexist, None);
+    assert!(signature.is_err());
+}